Multicomponent fibers are, in and of themselves, well known and have been used extensively to achieve various fiber properties. For example, multicomponent fibers have been formed of two dissimilar polymers so as to impart self-crimping properties. See, U.S. Pat. Nos. 3,718,534 to Okamoto et al and 4,439,487 to Jennings. Multicomponent fibers of two materials having disparate melting points for forming point bonded nonwovens are known, for example, from U.S. Pat. No. 4,732,809 to Harris et al. Asymmetric nylon-nylon sheath-core multicomponent fibers are known from U.S. Pat. No. 4,069,363 to Seagraves et al.
While various multicomponent fibers are known in the art, there still exists a need for multicomponent structures which enable a fiber to be "engineered" to suit particular end uses. It is towards providing such a fibre that the present invention is directed.
Broadly, the present invention is directed to multicomponent fiber having a primary core, and multiple secondary cores equidistantly radially spaced from one another and from the primary core. The primary and secondary cores are entirely embedded within (and thus completely encased by) a primary sheath. Optionally, the primary sheath may be entirely or partly surrounded by a secondary sheath. Thus, according to the present invention, the primary and secondary cores may be spun from polymers having distinctly different or complementary properties which are surrounded by a sheath or sheaths formed of another polymer(s) which protects the cores.
These and other aspects and advantages of the present invention will become more clear after careful consideration is given to the detailed description of the preferred exemplary embodiments thereof which follow.